One-pot millisecond preparation of quench-resistant solid-state fluorescence carbon dots toward an efficient lubrication additive

摘要

Currently, the investigation on preparation, photoluminescence (PL) mechanism and application of solid state fluorescent CDs (SSFCDs) is still in the preliminary stage. It is particularly urgent to research on this issue. Herein, a one-pot gaseous detonation method is employed to directly synthesize SSFCDs within milliseconds using citric acid (CA) and urea as precursors for the fast time. The SSFCDs exhibit dependent emission with the excitation/emission maximum of 370/452 nm. On the basis of studying the structural and optical characteristics of the SSFCDs and thermal annealing SSFCDs (A-CDs) as well as the properties of gaseous detonation, we speculate the PL mechanism and formation mechanism of SSFCDs. More importantly, the prepared SSFCDs without any purification as additives for poly(ethylene glycol) (PEG) obtain a super-low mean friction coefficient of 0.024 and wear scar diameter of 0.57 mm under 600 N at optimal concentration of 0.5 wt%, reducing by 60.7% and 19.7% respectively in comparison with that of pure PEG. The SSFCDs-based additives reported here display excellent friction-reducing and antiwear performance for PEG.